According to sources at Mumbai airport, information in this regard was recently gathered by external investigating agencies through diplomatic channels. Mumbai police have been instructed to take up the matter as top priority.

Sources added security will be beefed up at the Consulate and airport and city offices of Iran Airlines, and the State Reserve Police would be pressed into service to assist the airport and city police at both places.

High-security areas at the airport, like passenger and baggage check-ins of the airline, have been put on alert, and sniffer dogs will be used to ensure safety.

All employees of the Iranian government working at the consulate, the entire airline staff based in Mumbai and the flight crew operating through Mumbai airport will be given security cover, they added.

Though intelligence analysts have not yet been able to identify theterrorist groups have issued the threats, sources said a few Islamic terrorist groups operating within Iran and on its international borders were planning to launch a systematic offensive on Iranian government establishments.

This is the second time in recent years that security has been beefed up at Mumbai airport. Late last year, security was beefed up for all foreign airlines, especially those operating on the US, Europe and Gulf sectors following the US bombing of Afghan terrorist outfits and the threats of retaliation by international terrorist Osama bin Laden.